Dynamo-electric machine.



No. 706,00. Patented Aug. 5, 1902.

.|. BURKE.

DYNAMO ELECTRIC MACHINE.

(Application filed. June 26, 1900.)

(No llodel.)

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UNITED STATES PATENT OFFICE.

JAMES BURKE, OF BERLIN, GERMANY.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 706,017, dated August5, 1902.

Application filed June 26, 1900. Serial No. 21,671. (No model.)

To all whont it ntay concern:

Be it known that I, JAMES BURKE, a citi zen of the United States,residing at Berlin, in the Empire of Germany, have invented certain newand useful Improvements in Dy namo-Electric Machines, of which thefollowing is a full, clear, and exact specification.

This invention relates to dynamo-electric machines, and has particularreference to the pole-pieces thereof and to the manner of securing themagnet-windings upon the polepieces.

It is a well-known practice to provide the pole-pieces ofdynamo-electric machines with extensions forming enlarged end surfacesin order to cover a greater portion of the armature-surface than wouldbe covered were the cross-sectional area of the end of the polepiece thesame as that where the magnetwindingissupported. Variousarrangements ofsuch polar extensions are employed; but the most common constructioncomprises a separate extension bolted upon the end of the pole-pieceafter the magnet-winding has been slipped on. Such constructions,however, are objectionable, because the removal of the extension for thepurpose of taking out the magnet-windin g is often difficult withoutdismantling the machine and also because the extension cannot be broughtto the highest degree of magnetic saturation, owing to the reluctanceinterposed by the out between extension and pole-piece andthe fact thatthe extension is not directly surrounded and magnetized by thewindings.-

Therefore the present invention has for its object the construction ofpole-pieces having enlarged end surfaceswhich shall be of the maximummagnetic intensity and also the provision of means whereby the extensionmay be readily removed to permit the insertion or removal of themagnet-windings.

The invention will be more fully described with reference to the formsthereof shown in the accompanying drawings, in which Figure 1 is asectional View of a portion of a magnet-frame, showing pole'piecesembodying one form of myinvention. Figs. 2 and L are respectively detailside views of one of the extensions shown in Fig. 1 and of one of theexpansion-pieces. Fl". 4: is a sectional view of a magnet-frame, showingmodified forms of extensions upon the pole-pieces. Fig. 5 is a detail ofone of the extensions shown in Fig. 4; and Fig. (3 is a sectional viewof a magnet-frame, illustrating a modified arrangement for bracing theextensions.

Referring more particularly to the drawings, G represents themagnet-frame of the machine, and P P the pole-pieces thereof, whichordinarily are integral parts of the magnet-frame G, but may be whollyor partly separate therefrom, although in magnetic contact therewith.

In the drawings 1 have generally illustrated constructions in which thepole-pieces are provided with angular offsets or recesses into which theparts V V of the pole-pieces are adapted to be fitted, the parts P and Vbeing complementary to each other, so that the combined parts P V formthe pole-piece of the machine. These parts may be either solid orlaminated. So much of the pole-piece as is separate from themagnet-frame is preferably provided with an angular or beveled end 0,adapted to engage a complementary surface in the magnet-frame, in orderthat the parts will be held in better magnetic contact when braced, ashereinafter described. Upon the ends of the parts I and V of thepole-pieces are formed the extensions d d, which increase the endsurfaces of the pole-pieces toward the armature. ally serve in mostinstances to retain the magnet-windings s in proper position. In all theconstructions illustrated in the'drawings the extensions are integralwith some portion of the pole-piece that is surrounded by themagnet-winding, and thus it may be said that a portion of the extensionis in all cases directly under the influence of the magnet-winding, andsuch my preferred construction, for it insures a more intensemagnetization of the extensions than can be attained in constructionswherein the extension is attached to the pole-piece outside the windings, so that reluctance is interposed between extension and pole-piecebeyond the winding.

lhe extensions and pole-pieces are secured in proper position bysuitable means, such as the braces E. These braces may be arranged invarious ways--for illustration, by inter. posing them between oppositeextensions, as illustrated in'Figs. 1 and i, or by interposing Theextensions also incidentthem between the extension and the frame of themachine, as illustrated in Fig. 6. A desirable form of brace is shown indetail in Fig. 3 of the drawings. In such construction the claws a a areprovided with grooves c e, which are adapted to interlock with similargrooves ffon the ends of the polar extensions V. A screw 1) isswivelcdin one claw (t and screws into the other claw, the screw beingpreferably provided with a suitable portion g, adapted to receive awrench, and with a locking-nut 7t to prevent loosening of the screw byvibration.

In assembling the machine the coils are slipped over the pole-pieces andfitted in position and the extensions then inserted and braced inposition by applying the braces E.

It will be seen that the exact shape of the extensions V V, the relativeproportions of the parts P and V of the pole-piece, and the constructionand arrangement of the braces are not essential features of theinvention, as they will each be varied to meet individual conditions,and I therefore desire it to be understood that I do not herein limitmyself to the precise construction shown.

I claim- 1. In a dynamo-electric machine, the combination of pole-pieceand a separable extension therefor, the said extension being magnetizeddirectly by the magnet-winding of the machine, as set forth.

2. In a dynamo-electric machine, the combination of a separableextension for the polepiece, and means for magnetizing the same directlyby the magnet-winding of the machine, substantially as described.

3. In a dynamo-electric machine, the combination with the magnet-frame,of a polepiece, an extension which forms a portion of said pole-piece,the said extension and pole piece forming an unbroken magnetic circuit,a magnet-winding carried by the pole-piece, and means for bracing theextension and polepiece against movement, substantially as described.

l. In a dynamo-electric machine the combination with the pole-pieces, ofextensions therefor, said extensions being adapted to hold themagnet-windings in position, and braces between said extensions,substantially as described.

5. In a dynamo-electric machine, the combination with the pole-pieces,of enlarged extensions therefor, said extensions being adapted to retainthe magnet windings in position, and means for securing said extensionsagainst movement, substantially as de scribed.

6. In a dynamo-electric machine the combination with the pole-pieces, ofextensions therefor adapted to retain the magnet windings in position,and means for bracing the extensions against the magnet-frame, sub--stantially as described.

'7. In a dynamo=electric machine, the com bination with the pole-piece,of a separate extension fitted thereto and in magnetic con tacttherewith, the said extension constituting a portion of the pole piece,and a magnet-winding surrounding portions of both pole-piece andextension, substantially as described.

8. In a dynamo-electric machine, the combination with the pole-piece, ofan extension therefor, the said extension constituting a portion of thepole-piece, and a section of the extension being separable,substantially as described.

9. In a dynamo-electric machine, the combination with the magnet-frame,of a separate pole-piece having a diagonally-cut end adapted to befitted to and in magnetic contact with the frame, an extension a sectionof which is separable upon the other end of the pole-piece, amagnet-winding for said pole-piece, adapted to magnetize both the polepiece and the extension, and means for bracing the pole-piece in contactwith the frame, substantially as described.

10. In a dynamo-electric machine, the com bination with themagnet-frame, of pole pieces having one end diagonally out and adaptedto be fitted to and in magnetic contact with the frame, an extensionconstituting a portion of the pole-piece at the other end, a section ofsaid extension being sepa rable, magnet-windin gs upon said pole-pieces,and means for bracing the extensions against each other to hold thepoles in contact with the frame, substantially as described.

11. In a dynamo-electric machine, the combination with the pole-piece,of an extension constituting a portion thereof, a section of saidextension being separable, and a magnet-winding surrounding saidpole-piece, substantially as described.

12. In a dynamo-electric machine, the combination of a pole-piece havinga longitudinal recess, an extension for said pole-piece having a portioncomplementary to said recess, and a magnet winding surrounding saidpolepiece, substantially as described.

13. In a dynamo-electric machine, the combination of a pole-piece havinga longitudinal recess with an angular end surface, an extension for saidpole-piece having a portion complementary to said recess, and amagnet-winding surrounding said pole-piece, substantially as described.

14. In a dynamo-electric machine, the combination of a pole-piecehavinga longitudinal recess, an extension for said pole-piece having aportion complementary to said recess, a magnet-winding surrounding thepole-piece, and means for bracing the extension in the pole-piece,substantially as described 15. In a dynamo-electric machine, the combination with the pole-pieces having recesses therein, of extensionshaving portions complementary to said recesses, magnet-windingssurrounding the pole-pieces, and braces between the oppositely disposedextensions,substantially described.

16. In a dynamo-electric machine, the combination with the magnet-frame,of a separate pole-piece adapted to be fitted to and in magnetic contactwith the frame and having an extension upon its end, constituting aportion of the pole-piece, a magnet-Winding for said pole-piece, andmeans for bracing the polepiece in contact with the frame, substantiallyas described.

17. In a dynamo-electric machine, the combination of a pole-pieceextension separate from the pole-piece, and a magnet-winding surroundingthe same, substantially as described.

18. In a dynamo-electric machine, the combination with the pole-piece,of a separate extension therefor having a portion adapted to be fittedto the pole-piece, and a magnet-Wind- JAMES BURKE.

Witnesses:

HENRY HASPER, VVOLDEMAR HAUP'I.

